Black Friday & Cyber Monday Sales on Renter's & Owner's licenses - sale will end on the 1st of December 2020 at 12:00 UTC
16 November 2020 - Wouter van Reeven has officially joined the Astro Pixel Processor Team as a moderator on our forum, welcome Wouter 🙂 !
30 July 2020 - APP 1.083-beta1 has been released introducing Comet processing! This 1st beta has comet registration. The stable release will also include special comet integration modes.
9 July 2020 - New and updated video tutorial using APP 1.081: Complete LRGB Tutorial of NGC292, The Small Magellanic Cloud by Christian Sasse (iTelescope.net) and Mabula Haverkamp
2019 September: Astro Pixel Processor and iTelescope.net celebrate a new Partnership!
[Sticky] Creating a Bad Pixel Map
WOW what a great function !!!! I have always wondered what that is good .. I always tried it on the stacked picture and in full view .. but never in 100% view and on individual lights.
Great thank you!
It is a really nice feature yes, you can play around and check the effect before stacking. Same with flats applied or not.
Yes, so you can see if the flats are "working"
Just experimenting with it, which raised the question of what happens when I select "L-C-Registered" ?? Registering means aligning several lights with each other exactly, or am I confusing something? But I can only display 1 picture at a time. And I can see no changes between "L-Calibratet" and "L-C-Registered".
And what does "Normalized" or how do I normalize a light? I have already changed everything under 5) Normalize but I see no difference between Registered and Normalized.
L-C-registered is useful after registration is done. You can then go through the frames 1 by 1 to check if that worked. Or after registering a mosaic, checking what it did, change that if required and check again.
Is it useful to create multiple BPM for different iso settings of a DSLR?
I have two session of imaging with a canon EOS-6d, one at 3200iso, one at 6400iso
For each one i have acquired flat, bias, dark, so i create two set of masters. I use multi-session processing and APP let me to assign each master to a specific session, but not for BPM. APP seems to accept and use only one BPM: when i open a BPM file APP assign this file to all lights, and does not ask for which session.
Is that correct?
Good question, I don't think so no. A BPM will never be harmful for your data, so take the longest dark with the most noise to make it and it should work.
I have a question regarding the creation of the BPM. I've read that it requires the use of Dark frames and Flat frames, and that once created, it can be used many times (~ 1 year) before needing to create a new one. My question...Dark frames are typically taken after the Lights using the same exposure parameters under the same temperature conditions. But if the BPM file can be used over and over again, this would imply that exposure length and temperature condition is not important when creating the Dark frames needed for creation of the BPM. Is this correct? If so, it would also seem appropriate to use a very long exposure in order to heat up the sensor, making bad pixels more apparent - does that make sense?
The creation of a BPM isn't depended really on the conditions indeed. Ideally you take a few really long darks to get all the possible noise that can occur on your sensor. As a BPM is never destructive this will get you a better BPM.
is it correct that in version 1.082 the BPM is always created and automatically applied?
Yes, a BPM is now created automatically if the correct masters are available. You can copy/move that BPM to a folder where you also store your darks if you want, darks and a BPM can be used for multiple sessions. A BPM even for at least 6 months.
unfortunately I cannot load and see a finished stack result fits another session to test this BPM?
still V8.02..... do I have to delete all flats and darks first to load a finished stack?
You can load the BPM and just another single light, zoom in to the pixels on the BPM, then double-click the single light to load it in and switch between the normal view and "L-Calibrated" from the drop-down menu on top of APP. L-calibrated will show you what your calibration masters will do with that single light. It's a fast way to check if your calibration is working nicely.
sorry Vincent , I made a mistake, it works fine
But I have again the question: does it really make a difference to use BPM and darks, bias and flats?
Yes, it does. It will depend a little on the sensor, but when you zoom in just a little and then apply all those calibration files you'll see that difference yourself with the method I described above. It will remove a lot of the fixed pattern noise in your data. Flats will probably have the biggest effect of them all (when created properly which can be a bit of a challenge sometimes). You can correct for vignetting and dust with those. When properly calibrated you'll be able to stretch a bit more, get a nice signal out of the data etc.
Thanks Vincent !
I will try it !
Now I have one more question:
if the BPM is always created automatically anyway Is it still worthwhile to create a special one with, for example, a longer Darks exposure time? Does this then have to be exchanged for the automatically generated one?
Best is to use a BPM with something like a long exposed dark and even a good flat (if you have any cold pixels) and loading that in before starting to process. No BPM will be created then but the one you provided is used.